Sequential Gold-Catalyzed Carbene Transfer/Ring Closure: Oxidative Cyclization of β-(2-Alkynylphenyl)-α,β-ynones to Indenofuranones
作者:Navnath Rode、Fabio Marinelli、Antonio Arcadi、Tapas Adak、Matthias Rudolph、Frank Rominger、A. Stephen K. Hashmi
DOI:10.1002/adsc.201801082
日期:2018.12.21
β‐(2‐Alkynylphenyl)‐α,β‐ynones undergo a gold‐catalyzed oxidative two‐fold cyclization in the presence of N‐oxides to give 1,3‐disubstituted‐8H‐indeno[1,2‐c]furan‐8‐ones in good yields. This cascade process is triggered by a selective oxygen transfer from an N‐oxide onto the gold‐activated alkynone to generate a α‐dioxocarbene intermediate which, via carbene transfer across the remaining alkyne moiety
β-(2-炔基苯基)-α,β-炔酮在N-氧化物存在下经历金催化的氧化两倍环化反应,得到1,3-二取代-8H-茚并[1,2-c]呋喃-良率八分之一。这种级联过程是由选择性的氧气从N氧化物转移到金活化的炔烃上而产生的α-二氧卡宾中间体,该中间体通过卡宾转移到其余炔烃部分上,随后通过羰基氧的亲核攻击而环化1,3-二取代稠合多环呋喃的构建。